Just as a warning in advance: Mozilla upstream has decided to make the Rustprogramming language mandatory for Firefox 54 onwards [1].

Unfortunately, Mozilla currently has little interest to support Rust non-x86platforms in a stable manner which is why the Rust compiler rustc is currentlyreally usable on i386, amd64 and with some luck on arm64 [2].

Thus, it can be expected that Firefox 54 and newer will no longer run onany PowerPC platforms, especially 32-bit variants.

It's a sad state but Mozilla upstream has decided to make this cut whichwill also eventually see the removal of XUL support and hence the supportfor most of the popular Addons that exist in Firefox like Vimperator.

Mozilla will offer an Extended Support Release (ESR) based on an official release of Firefox for desktop for use by organizations including schools, universities, businesses and others who need extended support for mass deployments.